The present application claims priority under 35 U.S.C. xc2xa7119 on Japanese Application Nos. 2000-020949 filed Jan. 30, 2001 and 2001-311609 filed Oct. 9, 2001, the entire contents of each of which are hereby incorporated herein by reference.
The present invention generally relates to a liquid dilution device. More specifically, it relates to a liquid dilution device for diluting a special liquid.
Liquid dilution devices have been used to dilute special liquids such as a chemical liquid or detergent, with a diluent such as water. Generally, a liquid dilution device includes a diluent passage for allowing passage of water (water), a negative pressure generating section formed in order to generate negative pressure midway along the diluent passage, and a liquid introduction passage connected at one end to a special liquid tank, formed inside a body. By causing water, for example, to flow in the diluent passage due to the negative pressure generated in the negative pressure generating section, and the special liquid is mixed with the water or the like to be diluted.
In known systems, since, depending on the special liquid, it may be desirable to increase the dilution factor of that liquid, various methods having a high liquid dilution factor have been considered.
Firstly, it has been considered to fix jets inside a hose connecting a special liquid tank to the liquid dilution device, and to interchange these jets. However, the process involved in a user changing the jets is inferior, both with regard to efficiency and interchangeability. Also, in the even that dilution factor is increased, it is necessary to reduce the diameter of the jets. But the diameter of the jets can only be made so small, beyond which it is not possible to increase the dilution factor. It has also been considered to provide a dilution factor adjustment mechanism separately from the liquid dilution device. But in this case, there is the drawback that the device becomes large overall.
Secondly, it has been considered to provide dilution factor switching device in the liquid dilution device itself. A known liquid dilution device provided with dilution factor switching device is shown in FIG. 4 and FIG. 5, and the switching device itself is shown in FIG. 6.
Inside the body 60, there is formed one diluent passage 62 for introducing a diluent, such as water. This diluent passage 62 includes a venturi section 64 formed at a mid-point as a negative pressure generating section having the smallest cross sectional area, and a diffusion section 66 formed at a downstream side of this venturi section 64. A connecting passage 68 for connecting the diffusion section 66 and the outer side of the body 60 is formed in the body 60.
A disc 72, held between the body 60 and a holding member 70, is provided on the outer side of the body 60 in the vicinity of an opening section of the connecting passage 68, as dilution factor switching device. This disc 72 is rotatably attached to the body 60 and the holding member 70 via a bearing 76, centering around a shaft 74 as fixing element for fixing the holding member 70 to the body 60. As shown in FIG. 6, a plurality of jets 78, respectively varying in diameter, are formed in this disc 72 on the same radius from a rotation center position.
In addition to the holding member 70, a liquid introduction device 80 is provided on an opposite side to the body 60 so as to sandwich the disc 72. The liquid introduction device 80 is fixed to the body 60. This liquid introduction device 80 is formed from a first body 82 and a second body 84, and a liquid supply passage 86 connecting to a special liquid tank, not shown, is formed inside the first body 82 and the second body 84. This liquid supply passage 86 is connected to a connecting passage 68 of the body 60 through a jet 78 formed in the disc 72.
A ring shaped seal member 88 is attached at positions of the body 60 meeting the disc 72 and at positions surrounding the disc 72 and at positions surrounding the connecting passage 68. This ring shaped seal member 88 is for preventing leakage of water from the diluent passage 62 from a joining surface of the body 60 and the disc 72. A ring-shaped seal member 90 is attached at positions of the body 82 of the liquid introduction device 80 meeting the disc 72 and at positions surrounding the liquid from the liquid supply passage 86 from a joining surface of the body 82 of the liquid introduction device 80 and the disc 72. An elastic member 92 is provided at a position of the body 60 meeting the disc 72 and at a position separated from the ring shaped seal member 88.An elastic member 94 is provided at a position of the holding member 70 meeting the disc 72 and at a position separated from the seal member 90 These elastic members 92 and 94 act to prevent the disc 72 from leaning towards either the body 60 or the holding member 70.
The connecting passage 68 of the body 60 and the liquid supply passage 86 of the liquid introduction device 80 are connected through the jet 78 by lining up one of the plurality of jets 70 formed in the disc 72 with the connecting passage 68 of the body 60. In this way, if the connecting passage 68 and the liquid supply passage 86 are connected through the jet 78. Special liquid is introduced from the liquid supply passage 86 into the diluent passage 62 by negative pressure generated in an enlarged section 66 of the diluent passage 62. At this time, it is possible to vary the flow amount of the special liquid passing through the jet 78 to change the dilution factor, by rotating the disc 72 to line up one of the plurality of jets 78 with the connecting passage 68 and the liquid supply passage 86.
In the case of using the disc 72 in the dilution factor switching device, the two surfaces of the disc 72 are sealed by seal members 88 and 90. Since each of the jets 78 of the disc 72 is sealed by the ring shaped seal members 88 and 90, it is not possible to bring each of the jets 78 close to the center of rotation of the disc 72. This means that, as shown in FIG. 5, there is the drawback that the diameter of the disc 72 becomes larger than the diameter of the body 60 to increase the overall size of the device, and it becomes impossible to install a device of such a large size in a mains water tap.
Further, it is not possible to bring the jets 78 close to the center of rotation of the disc 72, because the disc 72 swings about the rotation position. When the disc is rotated causing variations in the distance between the disc 72 and the seal members 88 and 90, there is the drawback that sealing of the special liquid from the liquid introduction device 80 is not actually performed.
The present invention is intended to solve one or more of above described problems, and/or other problems. An object of the present invention is to provide a liquid diluting device. In one embodiment, a liquid diluting device includes a small and simple structure. Preferably, the liquid diluting device is capable of performing sealing; and/or is capable of easily altering a diluent concentration.
A liquid diluting device of one embodiment of the present invention includes a diluent passage formed in a body, and a negative pressure generating section formed in the diluent passage. It further may include a connecting passage, with one end connecting to the negative pressure generating section and another end connecting to an outer side of the body, formed in the body. A cylindrical dial, for closing off the connecting passage, may be rotatably attached to the outer side of the body. Jets, including different diameters passing through from inside to outside at a plurality of positions confronting the connecting passage, may be formed in the dial. A liquid introduction device forming a liquid supply passage for special liquid is attached to the body so that the liquid supply passage is positioned facing the connecting passage and the connecting passage. Finally, the liquid supply passage may be connected together through jets of different cross sectional area by rotating the dial.